Extracorporeal membrane oxygenation for influenza-associated acute respiratory distress syndrome.

BACKGROUND: Extracorporeal membrane oxygenation (ECMO) therapy for patients with influenza A (H1N1)-related acute respiratory distress syndrome (ARDS) has been described once all other therapeutic options have been exhausted. The current report reviews our institutional experience and lessons learned in 18 consecutive patients.

METHODS: Between December 2009 and March 2011, 18 patients underwent ECMO therapy for severe H1N1-related ARDS. Mean age was 40 ± 18 years (range 4-67 years). Ten patients (56%) received venoarterial cannulation (v-a ECMO) while venovenous cannulation (v-v ECMO) was initiated in the remaining patients (n = 8, 44%). To identify risk factors of adverse outcome, univariate analysis was performed for clinical parameters.

RESULTS: Successful ECMO weaning was possible in 44% (n = 8) of patients and overall mortality was 61% (n = 11). Seven of the eight patients who could be successfully weaned from ECMO support fully recovered. Survival within the v-a ECMO group (60%) was superior to the v-v ECMO group (13%; p = 0.06). Two patients (11%) required re-exploration of the axillary artery cannulation site. No further adverse events associated with ECMO implantation occurred. Outcome was better when the time of severe deoxygenation (Pao2 < 70 mm Hg) despite maximally invasive respiratory support to ECMO implantation was less than 6 hours (odds ratio: 2.4; p = 0.05).

CONCLUSIONS: ARDS associated with H1N1 remains a devastating clinical picture. In our hands, ECMO support offered survival to 40% of patients with otherwise fatal prognosis. While v-v ECMO remains the method of choice for patients suffering an isolated ARDS in the setting of stable hemodynamic conditions, v-a ECMO may be considered if the clinical picture of ARDS is aggravated by systemic inflammatory response syndrome with the requirement of high dose vasopressor support.